Question

A 70-year-old man presents with long-standing lower urinary tract symptoms from benign prostatic hyperplasia (BPH). He reports severe nocturia and weak stream. Physical exam and prior ultrasound show a markedly enlarged prostate. He wishes to avoid surgery. Which pharmacologic regimen is most appropriate?

Answer 1

Correct Answers:

tamsulosin plus finasteride

Rationale :

🔹 This patient has severe, long-standing LUTS with marked prostate enlargement, making combination pharmacologic therapy the most appropriate non-surgical option.

🔹 Tamsulosin (α-1 blocker) relaxes smooth muscle in the prostate and bladder neck, leading to rapid improvement in urine flow and reduction in nocturia and weak stream.

🔹 Finasteride (5-α-reductase inhibitor) reduces dihydrotestosterone (DHT) levels, resulting in gradual prostate shrinkage, which is especially beneficial in significantly enlarged prostates.

🔹 Combination therapy is superior to monotherapy in patients with large prostates, as it slows disease progression, reduces the risk of acute urinary retention, and lowers future need for surgery.

🔹 This regimen aligns with the patient’s wish to avoid surgery while still receiving effective, evidence-based management.

❌ Why the other options are not appropriate

❌ Watchful waiting with lifestyle changes only

🔹 Suitable for mild symptoms, but inadequate for severe nocturia, weak stream, and marked enlargement.

❌ Tadalafil monotherapy

🔹 May improve LUTS, particularly with erectile dysfunction, but does not reduce prostate size and is less effective in severe BPH.

❌ Surgical consult is necessary despite patient’s wishes

🔹 Surgery is reserved for complications (e.g., urinary retention, renal impairment), not first-line when effective medical therapy exists

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Answer 2

Correct Answers:

Do not prescribe any PDE-5 inhibitor while he is taking nitrates

Rationale :

🔹 Concurrent use of nitrates and PDE-5 inhibitors (e.g., sildenafil, tadalafil) is absolutely contraindicated due to the risk of profound, life-threatening hypotension.

🔹 Isosorbide mononitrate and nitroglycerin increase nitric oxide, leading to vasodilation, while PDE-5 inhibitors prevent cGMP breakdown, dramatically amplifying this effect.

🔹 Even in patients with normal blood pressure and stable angina, the combination can cause sudden severe hypotension, syncope, myocardial ischemia, or shock.

🔹 No safe timing interval exists that reliably eliminates this risk in patients on chronic nitrate therapy.

🔹 The safest and most appropriate response is to withhold all PDE-5 inhibitors and discuss alternative erectile dysfunction treatments that do not interact with nitrates.

❌ Why the other options are incorrect

❌ Prescribe tadalafil instead, as it is safer to use with nitrates

🔹 Tadalafil has a longer half-life (up to 36 hours) and is equally contraindicated with nitrates.

❌ Allow sildenafil use as long as he separates it from nitrate doses by at least 4 hours

🔹 Separation does not eliminate the interaction risk; dangerous hypotension can still occur.

❌ Advise patient to monitor blood pressure if taking both sildenafil and nitrate

🔹 Monitoring does not prevent sudden cardiovascular collapse and is unsafe clinical practice.

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Answer 3

Correct Answers:

An adolescent with closed epiphyseal growth plates

Rationale :

🔹 Growth hormone (GH) requires open epiphyseal (growth) plates to stimulate linear bone growth, making therapy ineffective once the plates are fused.

🔹 Closed epiphyses represent an absolute contraindication because GH cannot increase height after skeletal maturity, regardless of dose or duration.

🔹 Administering GH in this setting offers no clinical benefit and exposes the patient to unnecessary risks such as edema, arthralgia, and glucose intolerance.

🔹 GH use after epiphyseal closure may increase soft tissue growth but does not affect stature, which is the primary therapeutic goal in adolescents.

🔹 Therefore, GH therapy should not be initiated once growth plates are closed.

❌ Why the other options are not absolute contraindications

❌ A child with untreated hypothyroidism

🔹 Hypothyroidism should be corrected before GH therapy, but it is a relative, not absolute, contraindication.

❌ A patient with type 2 diabetes and insulin resistance

🔹 GH can worsen glucose control, but it may be used with careful monitoring; this is not an absolute contraindication.

❌ A woman with HIV-associated lipodystrophy

🔹 GH is an approved indication for HIV-associated wasting/lipodystrophy.

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Answer 4

Correct Answers:

Hydrocortisone

Rationale :

🔹 Hydrocortisone is preferred for routine replacement in primary adrenal insufficiency because it most closely mimics endogenous cortisol in both potency and duration.

🔹 It has a short half-life, allowing dosing to replicate the normal diurnal rhythm of cortisol (higher dose in the morning, lower in the afternoon).

🔹 Hydrocortisone provides adequate glucocorticoid effects without excessive suppression or prolonged exposure.

🔹 It is well tolerated and easily adjusted during stress, illness, or surgery, which is essential in adrenal insufficiency management.

🔹 For these reasons, it is the standard first-line agent for cortisol replacement in adults.

❌ Why the other options are not preferred

❌ Dexamethasone

🔹 Extremely long-acting and potent, making it difficult to mimic physiologic cortisol patterns and increasing risk of overtreatment.

❌ Fludrocortisone

🔹 Primarily a mineralocorticoid, used to replace aldosterone, not cortisol.

❌ Methylprednisolone

🔹 More potent and longer-acting than hydrocortisone, making it less physiologic for routine replacement.

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Answer 5

Correct Answers:

Liver function tests, especially at initiation and dose increases

Rationale :

🔹 Ketoconazole inhibits adrenal steroid synthesis by blocking CYP450 enzymes, making it effective in Cushing’s disease, but it carries a high risk of hepatotoxicity.

🔹 Baseline liver function tests (LFTs) are required before starting therapy, with frequent monitoring during initiation and after dose increases to detect early liver injury.

🔹 Hepatotoxicity from ketoconazole can be severe and potentially fatal, sometimes occurring early in therapy, even at standard doses.

🔹 Prompt identification of elevated transaminases allows timely dose adjustment or discontinuation to prevent acute liver failure.

🔹 Because of this risk, LFT monitoring is the most critical safety strategy when managing patients on ketoconazole.

❌ Why the other options are less important

❌ ECG monitoring for QT prolongation only

🔹 QT prolongation is a concern, but it is not the primary or most critical monitoring priority compared with hepatotoxicity.

❌ Cortisol monitoring every 4–6 hours

🔹 Cortisol levels should be monitored periodically, but such frequent checks are unnecessary and not the main safety concern.

❌ Regular potassium checks

🔹 Electrolyte monitoring may be useful, but potassium abnormalities are less common and less dangerous than liver toxicity.

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Answer 6

Correct Answers:

Taking the medication in a fasting state

Rationale :

🔹 Levothyroxine absorption is maximized when taken on an empty stomach, ideally 30–60 minutes before breakfast, because food interferes with intestinal uptake.

🔹 Fasting conditions reduce binding and competition in the gut, allowing more consistent and predictable bioavailability.

🔹 Improved absorption leads to stable serum T4 and TSH levels, which is critical for effective hypothyroidism management.

🔹 Consistent fasting administration reduces the need for dose adjustments caused by variable absorption.

🔹 For these reasons, fasting intake is the standard recommended practice for levothyroxine therapy.

❌ Why the other options reduce absorption

❌ Taking the medication with milk

🔹 Milk contains calcium, which binds levothyroxine and impairs absorption.

❌ Co-administration with calcium supplements

🔹 Calcium forms insoluble complexes with levothyroxine, significantly decreasing absorption.

❌ Presence of celiac disease

🔹 Celiac disease causes malabsorption, often requiring higher doses, not improved absorption.

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Answer 7

Correct Answers:

To reduce risk of arrhythmias and cardiac strain

Rationale :

🔹 Levothyroxine increases metabolic rate and myocardial oxygen demand, which can place significant stress on the heart, especially in older adults or patients with underlying cardiovascular disease.

🔹 Starting at a low dose allows the cardiovascular system time to adapt gradually to increased thyroid hormone levels, reducing the risk of tachyarrhythmias, angina, and myocardial ischemia.

🔹 Rapid correction of hypothyroidism can precipitate atrial fibrillation or worsening heart failure, making cautious titration essential.

🔹 Gradual dose escalation with close monitoring of heart rate, symptoms, and TSH levels improves safety while achieving therapeutic goals.

🔹 Therefore, the “start low, go slow” approach prioritizes cardiac safety over rapid normalization of thyroid function.

❌ Why the other options are incorrect

❌ To prevent bone loss

🔹 Bone loss is related to chronic overtreatment, not initial dosing strategy.

❌ To ensure maximum absorption

🔹 Absorption depends on timing and GI factors, not starting dose.

❌ To avoid drug interactions

🔹 Drug interactions are managed by timing and medication review, not dose titration speed.

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Answer 8

Correct Answers:

Propylthiouracil

Rationale :

🔹 Propylthiouracil (PTU) carries an FDA boxed warning due to the risk of severe, acute liver failure, which can be fatal or require liver transplantation.

🔹 Hepatotoxicity with PTU can occur suddenly and unpredictably, even in patients without prior liver disease.

🔹 Because of this risk, PTU is not first-line therapy and is generally reserved for specific situations such as first-trimester pregnancy or thyroid storm.

🔹 Patients on PTU require close clinical monitoring and prompt evaluation if symptoms such as jaundice, dark urine, abdominal pain, or fatigue occur.

🔹 The boxed warning highlights that the risk of liver injury outweighs benefits in most routine hyperthyroidism cases.

❌ Why the other options are incorrect

❌ Lugol’s solution

🔹 Used short-term to reduce thyroid hormone release; no boxed warning for liver failure.

❌ I-131 (radioactive iodine)

🔹 Causes thyroid ablation, not hepatotoxicity.

❌ Methimazole

🔹 Preferred first-line antithyroid drug due to lower risk of severe liver injury compared with PTU.

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Answer 9

Correct Answers:

CBC with differential

Rationale :

🔹 Antithyroid drugs (methimazole, propylthiouracil) can cause agranulocytosis, a rare but life-threatening reduction in neutrophils.

🔹 A baseline CBC with differential helps identify preexisting leukopenia and provides a reference if the patient later develops fever, sore throat, or infection.

🔹 Early detection of declining white blood cell counts, especially neutrophils, allows for prompt discontinuation of the drug to prevent severe infection or sepsis.

🔹 Although routine CBC monitoring is not required, obtaining a baseline value before therapy is a critical safety measure.

🔹 This lab is therefore essential to help detect one of the most serious adverse reactions associated with antithyroid medications.

❌ Why the other options are incorrect

❌ Lipid panel

🔹 Lipid levels are not affected by antithyroid drugs and do not help detect acute adverse reactions.

❌ Serum calcium

🔹 Calcium abnormalities are not a known complication of antithyroid therapy.

❌ Hemoglobin A1C

🔹 Glycemic control is unrelated to the major toxicities of antithyroid medications.

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Answer 10

Correct Answers:

Current use of a strong CYP3A substrate drug

Rationale :

🔹 Paxlovid (nirmatrelvir/ritonavir) contains ritonavir, a potent CYP3A inhibitor, which can dramatically increase serum levels of drugs metabolized by CYP3A.

🔹 Concomitant use with strong CYP3A substrate drugs (e.g., amiodarone, certain antiarrhythmics, ergot derivatives, some sedative-hypnotics) can lead to life-threatening toxicity, including arrhythmias, respiratory depression, or severe hypotension.

🔹 This interaction represents a major and often absolute contraindication unless the interacting drug can be safely held or substituted.

🔹 Careful medication reconciliation is essential before prescribing Paxlovid to avoid serious adverse outcomes.

🔹 Because of these risks, active use of strong CYP3A substrates is the most important contraindication among the options.

❌ Why the other options are not major contraindications

❌ Age over 65 years

🔹 Older age is actually a high-risk group that benefits from Paxlovid, not a contraindication.

❌ Lactation

🔹 Paxlovid is not absolutely contraindicated in breastfeeding; risk–benefit assessment is used.

❌ Mild nausea during prior antiviral therapy

🔹 Mild gastrointestinal side effects do not preclude Paxlovid use.

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☑️ EXAM 3 2025

No.

❌ Why the other options are incorrect

3 :
Which patient scenario represents an absolute contraindication to GH therapy?

❌ Why the other options are not absolute contraindications

4 :
Which glucocorticoid is preferred for routine replacement therapy in adults with primary adrenal insufficiency?

5 :
A patient with Cushing's disease is started on ketoconazole. Which of the following monitoring strategies is most important?

6 :
Which factor most increases levothyroxine absorption?

❌ Why the other options reduce absorption

7 :
What is the rationale for the "start low, go slow" principle when initiating levothyroxine therapy?

8 :
Which antithyroid drug carries a boxed warning for risk of severe liver failure?

9 :
Which lab should be obtained before starting antithyroid therapy to help detect serious adverse reactions?

10 :
Which of the following is a major contraindication for prescribing Paxlovid?

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☑️ EXAM 3 2025

No.

❌ Why the other options are incorrect

3 : Which patient scenario represents an absolute contraindication to GH therapy?

❌ Why the other options are not absolute contraindications

4 : Which glucocorticoid is preferred for routine replacement therapy in adults with primary adrenal insufficiency?

5 : A patient with Cushing's disease is started on ketoconazole. Which of the following monitoring strategies is most important?

6 : Which factor most increases levothyroxine absorption?

❌ Why the other options reduce absorption

7 : What is the rationale for the "start low, go slow" principle when initiating levothyroxine therapy?

8 : Which antithyroid drug carries a boxed warning for risk of severe liver failure?

9 : Which lab should be obtained before starting antithyroid therapy to help detect serious adverse reactions?

10 : Which of the following is a major contraindication for prescribing Paxlovid?

3 :
Which patient scenario represents an absolute contraindication to GH therapy?

4 :
Which glucocorticoid is preferred for routine replacement therapy in adults with primary adrenal insufficiency?

5 :
A patient with Cushing's disease is started on ketoconazole. Which of the following monitoring strategies is most important?

6 :
Which factor most increases levothyroxine absorption?

7 :
What is the rationale for the "start low, go slow" principle when initiating levothyroxine therapy?

8 :
Which antithyroid drug carries a boxed warning for risk of severe liver failure?

9 :
Which lab should be obtained before starting antithyroid therapy to help detect serious adverse reactions?

10 :
Which of the following is a major contraindication for prescribing Paxlovid?